CONCISE SYNTHESIS OF CIS-THEASPIRONES AND TRANS-THEASPIRONES VIA OXONIUM ION-INITIATED PINACOL RING EXPANSION

Authors
PAQUETTE LA LANTER JC WANG HL
Citation
La. Paquette et al., CONCISE SYNTHESIS OF CIS-THEASPIRONES AND TRANS-THEASPIRONES VIA OXONIUM ION-INITIATED PINACOL RING EXPANSION, Journal of organic chemistry, 61(3), 1996, pp. 1119-1121
Citations number
35
Categorie Soggetti
Chemistry Inorganic & Nuclear
Journal title
Journal of organic chemistry → ACNP
ISSN journal
00223263
Volume
61
Issue
3
Year of publication
1996
Pages
1119 - 1121
Database
ISI
SICI code
0022-3263(1996)61:3<1119:CSOCAT>2.0.ZU;2-W
Abstract
The odoriferous principle of black tea has been produced from 2,2-dime thylcyclopentanone. The reaction sequence begins with 1,2-addition of 5-lithio-2-methyl-2,3-dihydrofuran to this ketone and immediate acid-c atalyzed ring expansion of the resulting carbinols to a separable pair of spiro ethers. Individual conversion of these diastereomers to a,P- unsaturated ketones is followed by tandem condensation with the methyl lithium-lithium bromide complex and oxidation with pyridinium chloroch romate.